WALLA WALLA — Federal officials are planning to evict Caspian terns from an island in Potholes Reservoir near Moses Lake to protect endangered salmon and steelhead.
A plan released by the Army Corps of Engineers and Bureau of Reclamation indicates they will work to stop the salmon-eating birds from nesting on Goose Island in Potholes Reservoir, as well as Crescent Island on the Columbia River in Walla Walla County, anticipated to begin in the spring.
Based on data collected from 2007-2009 from fish tags left on Goose Island after birds digest the fish, about 370 pairs of nesting terns ate on 14.6 percent of inland steelhead. In 2012, the Goose Island colony consumed at least 180,000 juvenile salmonids from the Columbia River, the most since 2010.
The goals of the project are to reduce the consumption rate of upper Columbia and Snake River steelhead, chinook salmon and sockeye salmon in the inland basin, as well as to prevent nesting at Goose and Crescent Islands and provide conditions suitable for Caspian colonies outside the inland basin.
The Corps plans to set up a network of ropes and flags at Goose Island to deter the use of the current nesting habitats in the first year. Workers will also be using active hashing, chasing the birds off daily from early March to July.
Workers would also be permitted to remove eggs from nesting areas although it is possible no egg collection would be necessary with daily hazing.
Reclamation may consider using a more permanent method to prevent nesting following the first year of the plan, which would including placing cobble or boulders to create unsuitable nesting areas for the birds.